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    <title>Document</title>
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    <script>
        let arr = [1, 3, 2, 5, 4, 9, 7]
        // 外层控制循环的趟数
        for (let i = 0; i < arr.length - 1; i++) {
            // 内层控制循环的次数
            for (let j = 0; j < arr.length - i - 1; j++) {
                if (arr[j] > arr[j + 1]) {
                    let temp = arr[j]
                    arr[j] = arr[j + 1]
                    arr[j + 1] = temp
                }
            }
        }
        console.log(arr);
    </script>
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